JP-A-2000-71533 discloses a construction that a sensor holder (12) for holding a sheet sensor (13) turns with one end thereof as a fulcrum interlockingly with an opening/closing operation of a holder portion (4) having a print head (8) or the like. A fulcrum portion (15) as a turning fulcrum is provided to one end portion of the sensor holder (12), and a holding shaft (17) is mounted to the other end portion. The holding shaft (17) is engagedly fitted in an elongated hole (22) of a link member (20) connected to the holder portion (4).
Under the state that the holder portion (4) is closed, the sensor holder (12) is disposed in proximity to a sheet feeding passage (10). At this time, the holding shaft (17) is engaged with a holding groove (18) of a holding plate (19) provided to the printer main body (1), and the sensor holder (12) is fixed to the position concerned.
When the holder portion (4) is opened, the engaging state between the holding groove (18) and the holding shaft (17) is released, and also the sensor holder (12) rotates interlockingly around the fulcrum portion (15) and separates from the sheet feeding passage (10).
In the conventional printer having the above-described construction, the holder portion (4) and the sensor holder (12) are connected and integrated with each other by a link member (20), and the sensor holder (12) is separated from the sheet feeding passage (10) interlockingly with the opening operation of the holder portion (4). The sensor holder (12) is also kept to be spaced from the sheet feeding passage (10) while the rink member (20) is opened.
The sheet feeding passage (10) is disposed under the above state. When the sheet concerned has a tendency of curl, it is necessary to manually press the sheet concerned when the sheet is disposed in the sheet feeding passage (10), so that the workability is low.
Furthermore, it is necessary to adjust the position of the sheet sensor (13) in accordance with dimensional change of the sheet. This adjusting work is carried out under the state that the sensor holder (12) is disposed in proximity to the sheet feeding passage (10). JP-A-2000-71533 has no description concerning this adjusting work.
In this type of printer, when the sensor holder (12) is disposed in proximity to the sheet feeding passage (10), the holder portion (4) covers the upper side of the sensor holder (12). Accordingly, it is impossible to manually operate the sheet sensor (13) directly. Therefore, an adjusting mechanism for allowing the sheet sensor (13) to be operated from the outer peripheral portion of the printer main body (1) must be added, and thus the structure is complicated.
Therefore, the present invention has an object to provide a printer in which a sheet can be easily and properly disposed in a printer main body even when the sheet concerned has a tendency of curl, and also a sheet sensor disposed at a detection position can be simply moved and adjusted manually when the dimension of the sheet is changed.